Device for plastic surgery of the mitral valve

ABSTRACT

An annuloplasty device for plastic surgery of the mitral valve to be implanted in subjects affected by valvular heart diseases causing stenosis and/or insufficiency, including at least one curved body, to be implanted coplanar with the native mitral annulus, characterized in that the curved body has at least two portions extended in different planes with respect to that in which the curved body lies, adapted to assist the heart surgeon in the operations of repair of the mitral apparatus of a patient affected by stenosis and/or insufficiency, the curved body having at least two descending portions to be inserted inside the mitral orifice, adapted to provide a grip for the anchoring of a prolapsed leaflet and/or of a biological tissue biocompatible with the human organism and/or of tendinous elements, when the device is applied to the damaged mitral apparatus of a patient.

FIELD OF THE ART

The present invention refers to a medical device and in particular to a device for plastic surgery to be applied to the mitral apparatus of subjects affected by valvular heart diseases causing stenosis and/or insufficiency.

STATE OF THE ART

The substitution of the mitral valve and the mitral repair are “open heart” operations executed by heart surgeons in order to treat a stenosis (narrowing) or an insufficiency (loss) of the mitral valve. This is the inlet valve for the left part of the human heart which, as is known, is substantially composed of four chambers: two pumping chambers, i.e. the ventricles, and two filling chambers, i.e. the atria. From the right ventricle, blood is thrust into the pulmonary circulation, from which it exits enriched with oxygen, while the left ventricle pumps blood into the systemic circulation, up to the periphery. The blood is correctly driven, from the ventricles to the circulation and from the atria to the ventricles, by means of systems that prevent the existence of flows in retrograde direction. These systems, known as heart valves, are the structures that regulate the flow of blood inside the heart. These are appendages of essentially fibrous tissue, covered with endocardium, which control the passage of blood through the orifices that connect atria with ventricles and the ventricles with aorta or pulmonary artery. The opening and closing of the valves is entirely tied with the intracardiac pressure variations. Indeed, there are no nerve controls of the activity of the valves, which are thus simply thrust by the blood flow itself. The main task of the heart valves is that of preventing, ensuring an effective and passive resistance, the reflux of blood towards the atria during the ventricular contraction or towards the ventricles during the diastolic phase. There are four cardiac valves, in particular: the tricuspid valve, the bicuspid or mitral valve, the aortic valve with three semi-lunar cusps and the pulmonary valve with three semi-lunar cusps. Of particular interest for the present invention is the mitral valve. Said valve has a diameter of over 30 mm, it regulates the blood flow between the left atrium and the left ventricle, has an orifice of 4-6 cm and has a slightly oval form, analogous to the tricuspid valve, it too of nearly oval form.

Unlike the latter, the mitral valve has two cusps or flaps. A larger one is arranged forward and medially, which corresponds to the front and left wall of the septum, which guards the aortic orifice and is termed front aortic cusp. The other, smaller cusp is placed in the back and laterally, corresponds with the rear wall of the left ventricle and is called rear cusp.

In general, the incorrect functioning of the heart valves, which is defined valvular heart disease, is substantially manifested in two forms. One form, stenosis, is represented by an incomplete opening of the valve, involving the passage of blood into a smaller-than-normal orifice; another form, insufficiency, is represented by an incomplete closure, involving the reflux of blood through the valve, which must instead be closed. Very often, stenosis and insufficiency coexist, to a different extent in the same valve, achieving the so-called stenoinsufficiency. It is further observed that valvular heart diseases can be congenital or acquired. The latter can be of degenerative, infective, ischemic, traumatic or secondary origin, with conspicuous dilation of the ventricle and/or of the large vessels. The course of valvular heart diseases is in most cases slowly evolutional, with a very long phase (years) completely without symptoms.

The diseases of the valves of the right part of the heart, i.e. of the tricuspid and pulmonary valves where a lower pressure operating condition is in force, are rare and generally due to congenital problems.

The diseases involving the mitral valve and aorta are instead much more frequent. Of course, the consequences of valve disease depend on the type of irregularity and the severity thereof. In any case, the most extreme consequence of each valvular heart disease is cardiac decompensation.

Even if difficult to generalize, it can be stated that each valvular heart disease passes through two phases: a first compensation phase, during which the heart implements a series of mechanisms in order to confront the problem, and a second which evolves towards cardiac insufficiency, when the adaptation mechanisms are no longer sufficient to maintain a suitable heart rate.

The resolutive treatment of valvular heart diseases is usually of surgical type: medical treatment has the objective of slowing the progression and/or controlling the symptoms in congenital and acquired valvular heart diseases, e.g. acquired following the prolonged assumption of diuretics and vasodilators, or of contributing to the clinical stabilization of acute valvular heart diseases. In most cases, the dysfunctions of the mitral valve are associated with degenerations due to an excessive weakness of the structure of the leaflets or of the tendinous cords, which can cause the elongation of the latter and in some cases also the breakage.

For example, a common pathological form of the mitral valve, which is encountered in many patients, is represented by the dilation of the left ventricle, generally involving an increase of the distance between the papillary muscles and the mitral annulus. This pathology consequently causes an increase of the tension of the tendinous cords and a lowering of the circular crown, of the valve, below the plane where said crown would lie in normal conditions. Conventionally and for the purpose of facilitating the comprehension of the invention described hereinbelow, this plane is arranged perpendicular to the direction of the blood flow. The lowering of the circular crown below the plane perpendicular to the direction of the blood flow, and the tension of the tendinous cords, cause the lacking or correct superimposition of the leaflets, i.e. of the mitral cusps, during the systolic phase.

FIG. 1( a) and FIG. 1( b) respectively show the left ventricle of a human heart in which the mitral valve functions correctly, and the left ventricle of a human heart in which the mitral valve functions incorrectly caused by an insufficiency due to the excessive dilation of the ventricle in question.

The various pathologies verifiable in subjects affected by valvular heart diseases almost always require that the operation pertaining to the valve repair or substitution is accompanied by an operation to be executed on the tendinous cords, with the intention of restoring a more physiological tension of the cords themselves. More in detail, the degenerative valve disease can be caused by a lengthening or by a breakage of the tendinous cords, i.e. of the support apparatus of the “normal” valve, or by a more general weakening of the valve itself (myxomatous degeneration), in which all the components of the valve are enlarged or elongated. The type of repair depends on the specific problem and can consist of the removal of broken valve segments, in shortening elongated cords, in implanting synthetic cords in place of those broken or elongated and still other actions. Almost always, a “ring” is implanted, of circa 3 cm size, which surrounds the annulus of the valve in order to consolidate the repair. When the mitral valve is overly damaged, to the point where repair cannot take place, it is substituted with an artificial valve such as a mechanical or biological valve known in the literature.

Currently, the state of the art attests that various devices have been achieved and developed for modifying the size of the mitral orifice, restoring a more physiological valvular activity. In any case, it is deemed that the devices currently in use and the operation methods associated therewith can be considerably improved, e.g. for the purpose of reducing the stresses associated with the implant of conventional rings, and in order to be able to induce a repair even in cases where the implant of conventional rings has been made impossible, for example due to partial or total calcifications of the mitral annulus, which make it difficult to implant the annular device, by means of suture, on the damaged mitral apparatus.

For such purpose, the present invention, described in detail hereinbelow, proposes a new device for plastic surgery of the mitral valve.

In particular, the invention proposes a device for the plastic surgery of the mitral valve that is decidedly versatile, due to its many various embodiments, with respect to the current annular systems employed. The device allows, for example, operating with success on the damaged mitral apparatus even in the cases in which a formidable calcification of the mitral annulus has been found, deep in the myocardium. In these cases, if one proceeds to execute a valve substitution, there would be the risk of perforating the myocardium. The present device, described hereinbelow, due to its particular conformation, reduces to a minimum the possibility that this type of damage can be verified. In particular, said device allows executing the repair of the damaged mitral apparatus without necessarily having to operate on the ventricular bottom, which is difficult to “reach”, at the height of papillary muscles and/or on the tendinous cords.

DESCRIPTION OF THE INVENTION

The present invention refers to a new and innovative medical device to be applied to patients affected by valvular heart diseases, and in particular affected by decompensation of the mitral valve causing stenosis and/or insufficiency, adapted to allow the fixing of the prolapsing valve leaflet directly or by means of artificial cords, to the prosthetic structure itself. The device, object of the present invention, allows simplifying and facilitating the entire operation, rendering the repair of the mitral valve entirely independent of the changes of the ventricular geometry both in the post-operative period and of the modifications due to the remodeling of the left ventricle itself. In the chronic pathology of the mitral valve, the geometry of the left ventricle is modified over time, pathologically adapting itself over time to the valvular defect. Such modifications commonly lead to hypertrophy and left ventricular dilation, but these pathological modifications are mainly reversible and partially or completely regress following the restoration of the correct valvular operation. Therefore, at the current state of the art, if artificial cords are used anchored on one side on the valve leaflet and on the other side on the papillary muscles, the length of the cords is defined based on the size and on the ventricular geometry which will very probably be modified in the post-operative period. In particular, the reduction of the volume of the left ventricle could cause an excessive prolapse of the cords applied since the distance between the repaired mitral leaflet and the subvalvular apparatus decreases considerably and unpredictably after the operation. The present patent application, describing an innovative medical device, overcomes the aforesaid critical states, allowing the fixing of the mitral leaflet, directly or by means of the cords, on the device itself; such device, given that it is substantially stable and independent, avoids all the critical states correlated with the modification of the volume of the left ventricle in the post-operative phase. More in detail the present invention refers to a device for the plastic surgery of the mitral valve capable of restoring, when implanted in the dysfunctional mitral apparatus, a more physiological cardiac activity, also in the cases in which the operation is risky, e.g. in the presence of calcification phenomena involving most of the mitral annulus. In particular, the present device is represented by a curved body made of a material that is solid though ductile and malleable and which is of course biocompatible with the human organism. The material must also have a sufficiently high “semi-rigidity” to allow the curved body to maintain its conformation unchanged following the stresses imparted by the heartbeats. The curved body is also to be applied on the plane where the native mitral annulus lies.

The device, object of the present industrial invention patent application, is distinguished from conventional devices, in particular due to its high versatility, which allows being able to use the device in question in various pathological situations, exploiting its structural variants which correspond to its preferred embodiments. The main characteristics that render said medical device versatile is substantially given by the presence of at least two descending portions present on the curved body. In the course of the present description, by descending portions it will be intended the portions of the device to be inserted, when the surgery treatment is executed, inside the mitral orifice. It is important to note that said descending portions 3 of the device 1 are shaped and sized in a manner such that, when inserted in the mitral orifice, they do not interfere with the correct ventricular activity of the heart and of the motility of the mitral cusps. The descending portions are thus to be implanted inside the mitral orifice and substantially act as an actual grip for the anchoring of broken or damaged tissues, or for the application of new biological tissues, e.g. bovine pericardium, to be extended on the dysfunctional valvular portion. Said descending portions can be extended inside the orifice, being directed parallel to the direction of the blood flow, which is assumed to be perpendicular to the plane delimited by the circular crown where the mitral annulus lies; or alternatively they can be moved away from said direction parallel to the blood flow, upward, i.e. towards the left atrium, remaining however within the mitral orifice. This characteristic of being able to vary the conformation of the device, depending on the verifiable cases, is as mentioned above substantially due to the malleability of the material constituting the present device. In a particular embodiment of the invention the curved body is represented by an annular portion having a profile similar to that of the common currently used rings for annuloplasty, from which two descending portions depart that are perpendicular to the plane where said annular portion lies, like shoe vamps. More in detail, in this embodiment the annular portion, when applied via suture, surrounding the mitral orifice, allows restricting the latter e.g. in cases of insufficiency, involving all of the advantages that the conventional rings already provide. In addition, due to the presence of the at least two descending portions, the annual portion allows being able to repair the dysfunctional tissue by anchoring, for example, a prolapsed cusp to said descending portions, thus restoring a more physiological cardiac activity, without having to necessarily intervene on the tendinous cords and/or on the valve apparatus. The possible breakage of the tendinous cords is indeed one of the possible causes of prolapse of the mitral leaflets.

Still in this embodiment of the present device, if the mitral leaflet is excessively retracted or damaged, it is possible to use the descending portions as grip for the implant of a new biological tissue, adapted to cover the natural mitral leaflet as an extension. More in detail the extension of biological tissue, such as bovine pericardium, can be applied to the mitral apparatus by joining via suture, on one side, said tissue to the perivalvular portion, and on the other hand to the at least two descending portions, in a manner such that said tissue represents an extension of the damaged natural leaflet. The versatility of the device, that is the object of the present industrial invention patent application, is made evident in the case in which, for example, the mitral annulus is excessively damaged, as occurs in the case of fibrocalcification, and the leaflets are excessively retracted. The calcified annulus indeed makes it difficult if not possible, or in any case of high risk, the implant of the conventional annular systems, since a soft substrate is missing on which it is possible to execute the suture of the annular device. The present device allows overcoming this limit due to a particular embodiment thereof, in which it is provided that the curved body of the device is represented by at least two curved independent portions, each comprising a descending portion directed perpendicular with respect to the plane where the curved portion integrated therewith lies. Said curved portions, each provided with a descending portion, are to be implanted on the mitral valve, at the height of the commissures, thus overcoming the need of an annular implant along the entire circular crown where the calcified native mitral annulus lies. Once the two curved portions are applied to the damaged apparatus, it is possible to apply the extension of tissue biocompatible, exploiting the possibility of “anchorage” of said tissue to the two descending portions. In another embodiment of the invention, in order to facilitate the anchorage of a prolapsed leaflet, or of a biological tissue to be implanted, said descending portions, always to be inserted at the height of the commissures, are bound to each other. More in detail, said descending portions are bound due to a binding element represented by a section of material, with which the present device is obtained, by joining the ends, directed towards the ventricle, of said descending portions. Still more in detail, this material section is oriented orthogonal with respect to said descending portions. This particular embodiment allows facilitating the “anchorage” of a prolapsed leaflet, or the implant of a biological tissue or another biocompatible tissue, to be fixed, by means of suture, in part on the present device, and in part on the perivalvular tissues of the damaged mitral apparatus. The versatility of the device described in the present document is also shown in another embodiment, in which the curved body is represented by a curved portion, to be applied on the plane where the mitral annulus lies. In this embodiment, the curved portion has the ends descending from said plane and inserted inside the mitral orifice, in a manner so as to superimpose the entire device on the damaged mitral leaflet. This embodiment of the present device has proven to be particularly useful when a prolapse is verified of a mitral leaflet following a breakage of the tendinous cords. The implant of the device allows arranging the prolapsed mitral leaflet in its native configuration, i.e. directed inside the mitral orifice and no longer towards the left atrium of the heart. This configuration is maintained due to a direct suture of the prolapsed leaflet with the two descending portions, or due to an indirect suture by means of tendinous elements, such as artificial tendinous cords, which on one hand bind the leaflet, and on the other the descending portions of the device in question. If it is necessary to substitute the native leaflet, it is possible to model the device described in the preceding embodiment, by varying the conformation of the descending portions, by way of a non-limiting example, by profiling the descending portions as a U, with the concavity turned upward, or as an L, or by providing one descending portion as a U and the other as an L. This particular induced profile allows supplying the descending portions on which it is possible to obtain multiple suture points with a possible biological tissue, to be implanted as an extension on said device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a front view of a longitudinal section of the left ventricle of the human heart. More in detail FIG. 1( a) shows a front view of a longitudinal section of a left ventricle which functions correctly, while FIG. 1( b) shows the front view of the longitudinal section of a left ventricle which functions pathologically due to an excessive dilation of the ventricle itself. The figure clearly illustrates the presence of the papillary muscles P₁ and P₂, of the tendinous cords 40, of the mitral cusps 50 as well as of a hypothetical plane 20 coplanar with the native mitral annulus, when the latter does not have damages. Also indicated is the direction 30 of the blood flow, perpendicular to said plane 20.

FIG. 2 shows a front view of a particular embodiment of the device 1 for plastic surgery of the mitral valve according to the present industrial invention patent application. In particular, FIG. 2 shows that the device 1 comprises an upper curved body 2, from which two descending portions 3 depart which are arranged perpendicular to the plane where said curved portion 2 lies. In the case of the figure in question, said curved body 2 is represented by an annular portion 4 similar to the common annular devices currently used for the annuloplasty of the mitral valve. Said portion 4 has an oval profile, and has, at the center of the two minor arcs defined by said oval profile, at least one descending portion 3, for each minor arc, to be inserted inside the mitral orifice at the height of the commissures. The annular portion 4 is instead to be implanted, analogous to the conventional annular systems, on the mitral annulus of the damaged valve apparatus.

FIG. 3 shows a front view of another embodiment of the device 1 for plastic surgery of the mitral valve, object of the described invention. In particular, FIG. 3 shows that the curved portion 2 is represented by at least two independent curved portions 5 to be arranged, in proximity to the commissures, on the native mitral annulus. As is observed from the figure in question, each curved portion 5 has a descending portion 3, to be inserted inside the valvular orifice, when said device 1 is implanted in the mitral apparatus of the patient affected by valvular heart disease. The figure shows that said descending portions 3 are extended orthogonal to the plane where said curved portions 5 lie.

FIG. 4 shows a front view of a particular embodiment of the device 1 for plastic surgery of the mitral valve. In particular, FIG. 4 shows the device 1 in an embodiment which represents an evolution of that described in the preceding FIG. 3. The device is differentiated from that described in FIG. 3 substantially due to the profile of the descending portions 3. More in detail, FIG. 4( a) shows that the descending portions 3 are shaped as an L, while in the case of FIG. 4( b), said descending portions 3 are shaped as an L, but converge until they define a section of material orthogonal to said descending portions 3, indicated herein as section 10. The latter is useful, for example, for providing a support on which biological tissue 8 is to be sutured, such biological tissue 8 to be implanted in the damaged mitral apparatus of a patient, or for restoring, by means of suture, the correct spatial configuration and conformation of a leaflet, possibly prolapsed following the breakage of the tendinous cords.

FIG. 5 shows a view of a further embodiment of the present device 1 for plastic surgery of the mitral valve. More in detail FIG. 5( a) shows a front view of the device 1 in which the curved body 2 is represented by a curved portion 6 to be extended in part on the native annulus, and in part inside the valvular orifice. More in detail, the curved portion 6 to be implanted on the mitral annulus has its ends as descending portions 3, which in the figure in question are indicated as 3′ and 3″. The latter are extended, moving away from the plane where the curved portion 6 lies, to be placed coplanar with the native annulus, inside the mitral orifice. The figure intends to show the possibility offered to the heart surgeon to be able to vary the conformation of said descending portions, profiling them in accordance with the verifiable needs. FIG. 5( b) is similar to FIG. 5( a), but shows a perspective view of the device 1 in this particular embodiment. More in detail FIG. 5( b) shows the conformation and the extension of the descending portions 3 with respect to the plane where said curved portion 6 lies. Said descending portions 3 can have a variable angle with respect to the plane coplanar with the portion 6, due to the fact that the material constituting said device 1 is a solid material that is sufficiently malleable to allow shaping the device 1, in accordance with the needs verifiable in patients affected by valvular heart diseases.

FIG. 6 shows a front and perspective view of a further embodiment of the device 1 for plastic surgery of the mitral valve according to the present invention. FIG. 6 in particular shows an evolution of the embodiment described in FIG. 5. More in detail, FIG. 6 shows a view of the device 1 in which the curved body 2 is represented by the curved portion 7, having its ends as descending portions 3, analogous to the portion 6 described in FIG. 5. Said descending portions 3, in this particular embodiment, are distinguished due to the fact that they are U-shaped with the concavity turned upward, or L-shaped with the ends converging, or L-shaped with the ends spaced, or due to the fact that they are profiled with one U-shaped and the other L-shaped. These particular profiles of the ends indicating the descending portions 3 serve to facilitate the implant of a biological tissue 8 (FIG. 6( e)) to be assembled, via suture, on a substrate that maintains the conformation and spatial extension of said tissue 8 stable over time, in a manner such that said tissue 8 represents an extension of the dysfunctional mitral leaflet, when said device 1 is applied to the mitral apparatus of the patient.

FIG. 7 shows a front view of a longitudinal section of the left ventricle of a human heart, to which the device 1 has been implanted for plastic surgery of the mitral valve according to a particular embodiment of the invention. More in detail, the figure shows the restoration of the correct closure of the mitral valve in systolic phase, following the application of an extension represented by the biological tissue 8 supported by the device 1, which comprises the curved portion 7 as curved body 2 to be arranged coplanar with the native annulus, and the descending portions 3 (not visible in the figure), U-shaped, and/or L-shaped, or one L-shaped and the other U-shaped, and adapted to fix said tissue 8 to the device 1 via suture, in a manner such that said tissue 8 represents an extension of the damaged native leaflet causing insufficiency.

FIG. 8 shows a front view of a particular embodiment of the device 1 for plastic surgery of the mitral valve according to the present industrial invention patent application. In particular, FIG. 8 shows that the device 1 comprises an upper curved body 2, from which two descending portions 3 in overturned “L” shape depart, initially arranged parallel and then perpendicular to the plane where said curved body 2 lies. In the case of the figure in question, said curved body 2 is represented by an annular portion 4 similar to the common annular devices currently used for annuloplasty of the mitral valve. Said portion 4 possesses an oval profile, and has, at the center of the two minor arcs defined by said oval profile, at least one descending portion 3, for each minor arc, to be inserted inside the mitral orifice at the height of the commissures. It is noted in the figure that the descending portions 3 occupy the partially central portion of the valvular lumen.

FIG. 9. FIG. 9( a) shows that the descending portions 3 first project towards the center of the lumen, then extend to the interior thereof with an angle of about 90°, giving rise to a substantially overturned L-shaped structure. In the case of FIG. 9( b), said descending portions 3 first project towards the center of the lumen, then extend to the interior thereof with an angle of about 90°, converging, until a section of material is defined orthogonal with respect to said descending portions 3, indicated herein with the number 10.

FIG. 10 shows a front view of the valve 1 according to the present patent application, in which it is observed that the curved body 2 has semi-elliptical form and from this at least two descending portions 3 with overturned “L” shape depart, coinciding with the commissures. In FIG. 10( a) said descending portions 3 tend in the lower part thereof to move closer together without however connecting. In FIG. 10( b), the descending portions 3 are instead connected on the lower part by means of the section 10. Said section 10 is useful for example for providing greater support, on which a biological tissue 8 can be sutured which is to be implanted on the damaged mitral apparatus of a patient; or section 10 is useful for restoring, by means of suture, the correct spatial conformation and configuration of a leaflet, possibly prolapsed following the breakage of the tendinous cords.

DESCRIPTIONS OF THE PREFERRED EMBODIMENTS

In all embodiments thereof, the device 1 for plastic surgery of the mitral valve, object of the present invention, comprises: a) at least one curved body 2 to be implanted, during the execution of the heart surgery treatment, on the plane where the native mitral annulus lies. Said plane, indicated herein as plane 20, is conventionally assumed to be orthogonal with respect to the direction 30 of the blood flow, and b), at least two descending portions 3 to be inserted, during the surgical treatment, inside the orifice of the damaged mitral apparatus. More in detail, said descending portions 3 move away from the plane where the curved body 2 lies, to which they are joined, in a manner so as be directed inside the mitral orifice.

In a first embodiment of the described invention, the curved body 2 of the device 1 for plastic surgery of the mitral valve is represented by an annular portion 4 having a profile similar to that of the common rings for annuloplasty currently used for facilitating the restoration of a functional and correct valve activity. Said device 1, in this embodiment, is characterized by the presence of at least two descending portions 3, like shoe vamps, which depart from said annular portion 4, generally having oval profile, in proximity to the center of the minor arcs of said oval form; in such a manner, when the device is implanted in the mitral apparatus of the patient affected by valvular heart disease, said descending portions 3 are inserted in the mitral orifice at the height of the commissures. As already mentioned in the course of the present description, said descending portions 3 are, in this embodiment as in all the embodiments of the present device 1, shaped and sized in a manner such that they do not interfere on the physiological ventricular activity of the human heart and of the normal function of the mitral leaflets.

This particular embodiment of the device 1 allows associating—with all the advantages obtainable with the already-known annular devices, and substantially involving the approaching of the mitral leaflets—the possibility of using said descending portions 3 as an actual grip, e.g. as a grip for a possibly prolapsed leaflet, or for anchoring a biological tissue, such as bovine pericardium, to be extended on the dysfunctional valve portion.

In a second embodiment of the device 1 for plastic surgery of the mitral valve, object of the present invention, the curved body 2, coplanar with the native annulus, is represented by at least two independent curved portions 5 to be implanted on the native annulus at the height of the commissures. From each curved portion 5, at least one descending portion 3 to be inserted inside the orifice departs, orthogonal with respect to said each curved portion 5. This embodiment is particularly useful when it is not possible to execute the stable implant of the curved body 2, e.g. of the annular portion 4, on the native annulus. This condition is widely diffused and usually corresponds to the case in which the mitral annulus is widely calcified, to the point where it is difficult and risky to apply the conventional rings, by means of suture, to the perivalvular tissues. In some cases, the calcification encountered is so formidable as to make any operation impossible, thus giving up the possibility to restore a correct cardiac activity, and leaving the pathology untreated. For such purpose, the present device, in this particular embodiment, allows operation on the damaged mitral apparatus even when the implant of the conventional devices is made impossible, thus restoring a decidedly functional valvular activity. Also in this embodiment, analogous to that described above, the two descending portions 3 act as a support system and as a source of grip for a possibly prolapsed leaflet, or for the fixing of a biological tissue adapted to simulate the activity of the dysfunctional native leaflet, or for another application.

In particular, in order to assist the surgeon in the operation of implanting a biological tissue biocompatible with the human organism, in a further embodiment, the curved portions 5 have the at least two descending portions 3, having the ends L-shaped. Said L-shaped portions 3 can also converge until a material section 10 is defined, adapted to represent a stable support on which the biocompatible tissue 8 can be sutured. Said section 10, in this embodiment, comes to extend inside the mitral orifice, orthogonal to said descending portions 3, without interfering on the physiological ventricular activity.

In a further embodiment, the device 1 for plastic surgery, object of the present document, is characterized in that the curved body 2 is represented by a curved portion 6 to be extended and implanted coplanar with the native annulus, and in that the descending portions 3 are represented by the ends of said curved portion 6. Said ends, i.e. said descending portions 3, are indeed moved away from the plane of the native annulus, being extended inside the mitral orifice. The angle of said descending portions 3, with respect to the plane of the mitral annulus, can be manually varied due to the properties of the material constituting said device 1. As mentioned above, said material is sufficiently malleable such that it can be variously shaped under the action of a mechanical stress impressed manually, and at the same time sufficiently rigid to resist the mechanical stressed impressed by the heartbeat cycle.

This particular embodiment of the device 1, for plastic surgery of the mitral valve, is particularly useful, by way of a non-limiting example, when it is necessary to execute the surgical operation, restoring the operation of a prolapsed valve leaflet. This outcome can be obtained by assembling the prolapsed leaflet to the lower portion of the device 1, which comes to be implanted on said leaflet. The assembly can occur in a direct manner, e.g. via suture of the leaflet with the descending portions 3 of the curved portion 6, or via indirect suture, i.e. by means of tendinous elements, such as artificial tendinous cords, which indirectly bind the device 1, and in particular its descending portions 3, to the valve cusp in question.

In still another embodiment of the present device 1 for plastic surgery, the curved body 2 is very similar to the curved portion 6 described in the previous embodiment, and is represented by a curved portion 7 which is distinguished from the curved portion 6, substantially due to the conformation and profile of its ends, indicating the descending portions 3. Said descending portions 3, in this particular embodiment, are U-shaped with the concavity turned upward, or L-shaped and/or a combination thereof. This particular embodiment is particularly useful when it is necessary to implant a biological tissue 8 that is biocompatible with the human organism and adapted to simulate the activity of a dysfunctional cusp, which, for example due to an excessive retraction, is unable to ensure a correct superimposition of the leaflets during the systolic phase of the ventricle. By way of a non-limiting example, the U-shaped descending portions facilitate the stable assembly, via suture, of the biological tissue 8 to said ends, in a manner so as to have said biological tissue 8 implanted like an extension of the damaged native leaflet, once said device 1 has been implanted in the dysfunctional mitral apparatus of the patient.

In all embodiments thereof, the device 1 for plastic surgery of the mitral valve, object of the present invention, is made of a material having a thickness comprised between 0.1 cm and 0.5 cm, and preferably is 2 mm with regard to the portion representing the curved body 2, and a thickness comprised between 0.05 cm and 0.5 cm with regard to the portions representing the descending portions 3. Preferably the descending portions 3 have a thickness of 1 mm.

In a further embodiment of the invention, the descending portions 3 are connected to the curved body 2 or to the annular portion 4, in a manner such to be initially extended for about two, eight millimeters, preferably three millimeters, towards the center of the annulus itself, before then completing an angle of about 90° so as to descend inside, analogous to the previously described embodiments, towards the floor of the left ventricle. This particular embodiment of the invention allows the descending portions 3 to be maintained separated from the heart wall, occupying the most central portion of the valvular lumen. The absence or the reduced presence of contact between the descending portions 3 and the heart walls ensures the reduction of undesired friction and rubbing, often a cause of future problems that can cause undesired side effects. The overturned “L” shaped progression of the descending portions 3 in fact eliminates the possibility that said critical states can be established, also eliminating the possibility of the onset of side effects due to the physical contact between said descending portions and the heart commissures. The two descending portions 3 therefore have a substantially overturned “L”-shaped structure, having an initial portion connected to the annular portion 4 or to the curved body 2, substantially placed on the same plane as the annular portion 4 or the curved body 2, and a descending portion 3 adapted to be inserted inside the mitral orifice at the height of the commissure. The descending portion 3 has, with respect to the plane identified by the annular portion 4 or by the curved body 2, an angle comprised between 80° and 100°, and preferably it has an angle of about 90°. In a further embodiment of the invention, the curved body 2 has a semi-elliptical form, as represented in FIG. 10, with an open portion. Also in this embodiment of the invention, the body 2 is substantially arranged on a plane from which, at the commissure, at least two descending portions 3 departing having overturned “L” shape. In this latter embodiment of the invention, said descending portions 3 can be free or connected together by means of the bridge 10, defined section 10, arranged on a plane parallel with respect to the plane on which the body 2 lies. In all embodiments thereof, the device 1 for plastic surgery of the mitral valve, object of the present invention, is made of a material having a thickness comprised between 0.1 cm and 0.5 cm, and preferably is 2 mm with regard to the portion representing the curved body 2, and a thickness comprised between 0.05 cm and 0.5 cm with regard to the portions representing the descending portions 3. Preferably the descending portions 3 have a thickness of 1 mm. The descending portions 3 in the present invention patent application have a length, intended as a depth extension inside the mitral valve, comprised between 0.5 and 3.5 centimeters, preferably between 1 and 2 centimeters. 

1. A device for plastic surgery of a mitral valve, to be implanted in subjects affected by valvular heart diseases causing stenosis and/or insufficiency, comprising: at least one curved body, to be implanted coplanar with the native mitral annulus, wherein said curved body has at least two portions extended in different planes with respect to that in which said curved body lies, adapted to assist a surgeon in the operations of repair of a mitral apparatus of a patient affected by stenosis and/or insufficiency, said curved body having at least two descending portions to be inserted inside the mitral orifice, adapted to provide a grip for anchoring a prolapsed leaflet and/or of a biological tissue biocompatible with a human organism and/or of tendinous elements when said device is applied to the damaged mitral apparatus of a patient.
 2. The device according to claim 1, wherein the curved body has an oval profile, said curved body being represented by an annular portion having profile similar to that of the common rings for annuloplasty currently used for restoring a functional and correct mitral valvular activity, and in that the at least two portions depart from said annular portion, being extended inside the valvular orifice when the device is implanted in the mitral apparatus of the patient, said annular portion having the descending portions directed, at the height of the commissures, like shoe vamps in a manner so as to form, with the plane in which said body lies, an angle comprised between 80° and 100°, said at least two descending portions departing from the center of the minor arcs of said oval profile.
 3. The device according to claim 1, wherein the curved body is represented by at least two curved portions to be arranged coplanar with the native annulus at the height of the commissures, said device comprising at least one curved portion to be arranged at the height of one valvular commissure and at least another curved portion to be arranged at the height of the commissure opposite to the first, and in that each curved portion has at least one descending portion to be inserted inside the valvular orifice, and extended in a manner so as to form an angle comprised between 80° and 100° with respect to the plane in which the curved portion lies, the portion departing from the center of such curved portion.
 4. The device according to claim 3, wherein the ends of the descending portions, turned towards the valvular orifice, are shaped as an L or they are shaped as two converging Ls, said ends defining, in the latter case, a section of material joining said descending portions and inserted inside the orifice, said device having the section extended inside the valvular orifice.
 5. The device according to claim 1, wherein the curved body is represented by a body defining an open curve to be implanted in part coplanar with the native mitral annulus and in part inside the valvular orifice, said curved body being represented by the curved portion, to be extended coplanar with the native annulus, and having the ends descending inside the orifice when said device is implanted, said ends of the curved portion representing the descending portions.
 6. The device according to claim 1, wherein the curved body is represented by a body defining an open curve to be implanted in part coplanar with the native mitral annulus and in part inside the valvular orifice, said curved body being represented by the curved portion, to be extended coplanar with the native annulus, and having the ends descending inside the orifice when said device is implanted, said ends of the curved portion representing the descending portions of the device and in that said descending portions are substantially U-shaped with the concavity turned upward, or they are shaped as an L, or they are shaped with one U-shaped and the other L-shaped.
 7. The device according to claim 1, wherein the portions descending towards the left ventricle have an overturned “L” shaped progression, being connected on the upper part to the annular portion or to the curved body, being centrally extended by two to eight millimeters, preferably four millimeters, towards the valvular lumen inside the mitral orifice, hence giving rise to the descending portion with respect to the plane identified by the annular portion or by the curved body, said descending portion having an angle comprised between 80° and 100°, preferably an angle of about 90°.
 8. The device according to claim 1, wherein it optionally comprises un biological tissue biocompatible with the human organism, adapted to be assembled, by means of suture, to the descending portions of the device.
 9. The device according to claim 1, wherein the tissue is made of bovine pericardium or of any other tissue, available on the market, that is biocompatible with the human organism.
 10. The device according to claim 1, wherein it is made of a material biocompatible with the human organism.
 11. The device according to claim 1, wherein it is made of a solid material that is sufficiently malleable so as to be manually modeled by the surgeon as required, and sufficiently rigid to maintain the conformation thereof unchanged following the stresses imparted by the heartbeat.
 12. The device according to claim 1, wherein it is made of a material having a thickness comprised between 0.1 cm and 0.5 cm, with regard to the portion representing the curved body, and a thickness comprised between 0.05 cm and 0.5 cm with regard to the portions representing the descending portions.
 13. The device according to claim 1, wherein it is made of a material having a thickness of 2 mm with regard to the portion representing the curved body, and a thickness of 1 mm with regard to the portions representing the descending portions.
 14. The device according to claim 1, wherein it has the descending portions of a length comprised between 0.5 and 3.5 centimeters, preferably between 1 and 2 centimeters.
 15. A method for using plastic surgery of the mitral valve to be implanted in subjects affected by valvular heart diseases causing stenosis and/or insufficiency, comprising the following steps: implanting a mitral apparatus in a patient affected by stenosis and/or insufficiency, the apparatus having at least one curved body coplanar with the native mitral annulus, and having at least two portions extended in different planes with respect to that in which said curved body lies, and inserting the at least two descending portions inside the mitral orifice, adapted to provide a grip for the anchoring of a prolapsed leaflet and/or of a biological tissue biocompatible with the human organism and/or of tendinous elements when said device is applied to the damaged mitral apparatus of a patient. 